This paper deals with the results of stage 1 clinical trials for sulfated aluminum phthalocyanine (PHS) (Photosens, Russia) in 1994-1996. The results of photodynamic therapy (PDT) of head and neck tumors (HNT), side effects and ways of their correction and prevention, as well as changes in doses of injected photosensitizer (PS), regimes of light irradiation, choice of laser and type of irradiation (surface or interstitial) are discussed. PDT have been provided in 42 patients (93 tumor sites) with different head and neck tumors. Fluorescent diagnostics of tumor, accumulation of PS in tumor, adjacent tissue has been fulfilled. Total 78 PDT sessions have been done. As a source of light we used: quantoscope, solid laser, krypton laser, tunable dye laser, He-Ne-laser. In 38 tumor sites (21 patients) -- 40.8% -- we had clinical response, in 27 tumor sites (16 patients) -- 29.0% -- we had partial response, in 28 tumor sites (8 patients) -- 30.2% -- we had no response. Our experience shows pronounced efficacy of PDT for HNT, except of melanoma. Providing PDT twice with the interval 24 - 72 hours when retention of PS is sufficient for treatment, did additive effect to the tumor, but didn't increase adjacent tissue damage.